Toshiba also extended its industry leadership in memory card solutions by unveiling the world’s first 4GB, 8GB and 16GB microSDHC UHS-I cards compliant with (SD 3.0), UHS50. Mass production of the new SDHC UHS-I cards and sample shipments of the new microSDHC UHS-I cards will start this November.

It's not entirely true. From what you wrote it only has fastest read speeds.
SanDisk Extreme III SDHC Class 10 has max 30MB/s read write speeds.
I have one of those babies in my EOS 550D and it really is blazing fast